5 Ways to Measure Body Fat Percentage

If you’ve been following BuiltLean.com, you know losing fat WITHOUT losing muscle is the only way to get lean. So how do you track if you are losing fat, or muscle, or both? The first place to start is by measuring your body fat percentage.

I have an overview of the 5 most common methods of how to measure body fat percentage below, along with the ONLY method to perfectly measure body fat percentage (I’ll bet you don’t want to use this method). While these 5 methods vary in accuracy, the key to assessing body fat levels is consistent measurements over time (repeatability) so that you can effectively track your progress.

Measure Body Fat Percentage #1: Skin Fold Caliper

The “skin fold” method measures your body fat percentage by pinching your fat with your fingers then measuring the thickness with a body fat caliper. The reading is given in millimeters, which you compare to a chart with age and gender to arrive at your body fat percentage. There are many different types of caliper tests, which range from only one site like with the Accumeasure Body Fat Caliper to a 7 site Jackson Pollack Method (some are as high as 12 sites).

Upside

Accurate

Dependable (when skilled at measuring)

Repeatable

Downside

Variability of measurement (same exact spot needs to used each time)

More than one-site test requires a skilled fitness professional (I’ve done these thousands of times!)

For people 35+ pounds overweight, fat may not fit within caliper, so it’s less accurate

Bottom Line
Skin Fold is hands down the most effective, accurate, practical method to measure and track your body fat percentage. The self-administered Accumeasure Body Fat Caliper retails for under $10 and is sufficient for most people.

Measure Body Fat Percentage #2: Bioelectric Impedance Analysis

Bioelectric Impedance Analysis, or BIA, determines the electrical impedance, or opposition to the flow of an electric current through the body. Muscle has high water content, and is highly conductive, while fat has lower water content and is not highly conductive. Based on the strength of the impedance along with height and weight metrics, the BIA scale will estimate fat-free body mass and body fat percentage.

Many consumer weight scales like Tanita Body Fat Monitor Scale also come with BIA capabilities, and there are others that require holding the BIA device in your hands. Because the BIA test is based on body water balance, your state of hydration can impact the level of accuracy.

Upside

Very easy to administer

Inexpensive (most weight scales around $50 or even less have BIA)

Downside

Questionable Accuracy

Variability of results dependent on hydration level

Bottom line
If you can’t use calipers, this is a far second option. If you have a high body fat percentage (calipers can’t fit around your fat pinch), or you have 35+ pounds to lose, start with BIA, then move to calipers. BIA readings for those with low body fat tend to be completely inaccurate.

Measure Body Fat Percentage #3: Anthropometric

This method uses body circumference measurements to estimate body fat percentages. The U.S. Navy method takes waist, neck, and height circumference for men and hips, neck, and height for women.

A U.S. Navy Method calculator is available on this website where you can input your measurements on right hand column. If you don’t have a cloth measuring tape, you can purchase a MyoTape Body Tape Measure, which I’m using to measure my waist in the picture to the right.

Upside

Easy to Administer

Cheap

Downside

Questionable Accuracy (Body fat is not directly measured)

Bottom Line
I would consider this method the least accurate because it doesn’t directly measure body fat (or even attempt to). For example, I have around 6% body fat using calipers, but according to anthropometric, my body fat is around 11.5%. If you don’t have a BIA scale, or calipers, it can be a decent start.

Measure Body Fat Percentage #4: Hydrostatic Weighing

This method is considered the “Gold Standard” (+/- 1.5% error) of body fat measurement that requires being submerged in a specialized tank of water. Because bone and muscle are more dense than water, a person with a larger percentage of fat free mass will weigh more in the water and have a lower percent body fat. Conversely, a large amount of fat mass will make the body lighter in water and have a higher percent body fat.

Accuracy of the reading is contingent upon blowing all the air out of the lungs during pretest screening. The test takes about 20-30 minutes, costs around $100-150, and is available at research labs, universities, or hospitals.

Upside

Very accurate, considered Gold Standard

Downside

Impractical

Expensive

Not repeatable (unless you liked repeatedly getting dunked in a tank and spending $150)

Bottom Line
If you are extremely curious to get the most accurate measure of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, Hydrostatic Weighing may make sense. Otherwise, it’s far too impractical.

Measure Body Fat Percentage #5: DEXA Scan

Dual Energy X-ray Absorptiometry known as DEXA is fast becoming the “new” gold standard of body fat measurement because it’s based on a three-compartment model that divides the body into total body mineral, fat-free soft (lean) mass, and fat tissue mass. Hydrostatic Weighing on the other hand only uses a 2 compartment model (fat free mass and fat mass).

DEXA also allows for body fat distribution analysis, so you can figure out with precision how fat is distributed in various parts of your body. In the past, DEXA was only used to measure bone mineral density for ostopenia and osteoporosis in older individuals. The procedure uses a body scanner with low dose x-rays, so it’s completely safe, and takes about 10-20 minutes.

Bottom Line
Similar to Hydrostatic Weighing, if you are extremely curious to get the most accurate reading of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, DEXA may make sense. Otherwise, it’s far too impractical and expensive.

All these methods rely on algorithms to convert a measured parameter into an estimate of body fat percentage, so none of them are perfect. Algorithms have variation based on how the underlying assumptions and formulas apply to different populations.

So what’s the only way to measure body fat with perfect accuracy? Well, cutting open a body and examining the fat, like with a cadaver. Seriously, that’s really the only way to measure body fat percentage most accurately.

I plan on digging deeper into each method in future articles, but I hope this was a helpful overview of each method.

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Awesome article. Very informative. I have one of the Bioelectric Impedance Analysis (BIA) scales at home. I was searching the internet to figure out: 1: how accurate it really is and 2: what a healthy body fat percentage falls under for my gender, age, and height. This article was great. Thanks!

I’m still shocked that my body fat percentage puts me in the “athletic/lean” category. I’m at 17%. Most of my life, I was a sporadic exerciser (at best) and a couch potato (at worst). Highest body fat percentage was around 30%. I got snapped into reality when my mom died of lung cancer back in ’07 because she took terrible care of herself. Nothing like your own immortality to make you put the remote down and grab a pair of dumbbells. BTW, I’ll weigh in on the whole “is that your stomach/” comment too. Impressive but I like the fact that you’re not totally bulging with muscles. Most women would agree with me, I think. Even with muscles, too much of a good thing is not attractive. Just my two cents. Thanks for the informative article too.

I’m a 5’7″ 156lb 42 year old woman and I’m completely confused! Using a body fat caliper on suprailiac fat places me at 22.8% bodyfat. Ok great, I’m feeling pretty good about myself. Now I step on the BIA scales and it puts me at 37% body fat!! And that supposedly is low because I have metal implants in my back which according the the Tanita website will give a slightly lower reading to body fat percentage. What a porker. Soooo, then I go to an “input your measurements/weight/height” website calculator online…and come up with….31%. Hmmm. So I have somewhere between, I assume, 22.8% and 37% body fat. Either “lean” on one end of the spectrum, or “overfat” on the other. I’m feeling a little schizophrenic. Is this kind of variation normal for different body fat measurement methods? I understand that no method is completely accurate, but this is kind of ridiculous!

@xnihilo – what you are experiencing is believe it or not completely normal. I don’t even consider BIA to a be a viable option, unless you have too much body fat where calipers don’t work. For example, I’m MAX 8% body fat, probably 7% (I have very little fat on my body) and a BIA scale calculated my at 16%. I would go with calipers hands down because you are physically pinching the fat on your body and measuring the skin folds, which is far more accurate in general, especially if done by a skilled professional. The calculators online I would definitely not pay attention to as well. If you are reasonably fit and have some muscle, at 157lb and 23% body fat, your LBM is 120lb. That sounds reasonable to me. Even 115lb LBM would put you at 26% body fat, which is within a normal range. Don’t get annoyed/frustrated/confused with these body fat measurement. Check out this article for some more info: http://www.builtlean.com/2010/08/03/ideal-body-fat-percentage-chart/.

I used the body fat analyzer on my scale for years – measured 26%. When I really got serious about running and lifting on a routine basis, my body fat percent barely budged even though I visually noticed results. I went to my chiropractor who had a different setup with a computer and lots of leads. He said it was the current gold standard (last year). It measured 16.4% BF! Moral of the story – scales are no where near accurate. Hope this helps!

All measures taken within a half hour
Ozeri scale – 43.3%
Omron handheld – 39.5%
Accumeasure single point – 30.7 (self measured)
Jackson/Pollock 4 points – 30.83 (my son helped measure)
I am a pretty big guy 5’9″ and 278 lbs. I’m very active but still have a lot of fat. I’ve found that the Omron will fluctuate almost 3% in a single 24 hour period. The Ozeri is pretty much worthless to me – It supposedly measures water, fat, muscle, and bone weight. It shows me as having less than 4 lbs of bone – not likely.

The accumeasure and Jackson Pollock are fairly consistent with each other and from day to day. I don’t know if they are accurate about actual percentage but they are more reliable for historical comparison of myself over time. The electronic devices only frustrate me with such wild readings.

I have a scale that was relatively cheap that measures BIA. It came with a very informative insert describing the limitations of BIA, especially for athletic individuals with high body muscle and low body fat. It has an “athlete” mode, which you select if you exercise a certain amount per week (I forget the exact numbers, but I think it was at least 30 minutes of moderate to intense exercise 5 times a week) and have a resting heart rate below 60. The difference in body fat measurement if I toggle between the two is huge (“normal” mode measures me at over 50%–not likely, and “athlete” gives me 22%) and when I crunch the numbers to get at how many pounds of fat and muscle I have on my body, the “athlete” mode makes much more sense.

Have you heard of this? It must use a different algorithm or something–do you think it’s reliable?

@Rebecca Scarlett – Yes, I’m keenly aware of what you describe. I do not use BIA for reasons I describe in the article as an accurate measurement. I strongly prefer measuring fat directly using skin fold calipers and I would encourage you to find a couple smart trainers who can do at least 3-7 site body fat test on you to get a decent estimate. With that said, if you are able to track changes in your body fat, than BIA can at least be used to track changes.

I’m 5’7″ and weigh 160lb’s but my fat on the Omron scales is 42.5%. I am sure that this is wrong. Even if I was morbidly obese it’s off the charts. I’m on the border of just overweight on BMI index. Any ideas?

I ordered the Accumeasure skinfold caliper as you recommended, and already had a Tanita bioimpedance scale. Interestingly, unlike everyone else’s experience, the calipers came up with almost exactly the same measurement (15.9%) as the scale (16.0%). Almost makes me wonder if I did the calipers wrong…although I did get the same caliper measurement several times in a row!

One thing I’ve noticed is that the accuracy of various anthropometric methods seems to vary widely from person to person. I use the table from the back of Barry Sears’ book “Enter The Zone” – or, to be more precise, I use a spreadsheet which works from a best-fit analysis of the table. It uses weight and the difference between belly and wrist measurements. In several within-30-minutes comparisons over the course of a couple of years, it never differed from skinfold calipers (4-site method) by more than 0.8%; usually the difference was less than 0.5% (my body fat ranged from 25% to almost 35% over that span). However, when I tried that same comparison on a friend, the difference was over 4%.
So, “caveat mensor” – let the measurer beware.

Hey George, yes I have heard of that device and I should add it to this article. There are a lot of them around – http://www.bodpod.com – in the top right hand corner you can search for facilities in your city/state. My understanding is DEXA is more accurate, but the bod pod is very easy and many athletic teams use the body pod.

I know that BIA devices can be wildly inaccurate, but I am confused about one thing. I am 5’7″, 135 pounds, wear a US size 6. I have a Withings scale that says my BF% (not body fat pounds) ranges from 30-32% (42 pounds of fat). The Weight Watchers scale at the beach condo says my BF% is about 22% (30 pounds of fat).

Why is there such a large discrepancy between the two BIA devices? Should I totally disregard them both? I don’t belong to a gym or know any trainers, or I would try the caliper device.

@Maria – I would suggest trying out the accumeasure skin fold caliper. Given your height/weight and assuming you lift weights a couple times per week and exercise, my guess is you are much closer to 22% than 30%. So assuming a relatively low LBM for your height of 100lb, that would mean you have 25% body fat. I would take the wild guess you had 105lb LBM, which leaves you at 22% body fat. As I state in the article, BIA is very unpredictable. There are a number of reasons why the readings may be different, including the settings you have, such as normal vs. athletic, or the strength of the electric current. I’m going to be adding an AWESOME post that shows 5, or so women and the relative body fat percentages of each, so I’ll go down the line and show a woman at 30%, then 25%, then 20%, then 15%, then 12%. It will take some time to add, but should be really good!

Maria – In addition to the things Marc mentioned, I’ve noticed that foot dampness can cause a huge difference. The instructions for a BIA scale I used to have said feet should be slightly damp but not wet for best results when getting a body fat measurement. I could easily get 10-12% variance in consecutive readings just by varying how damp my feet were.

Thanks so much for the replies! I read this, and actually ordered the caliper Monday night from Amazon, and received it this afternoon (with the Myotape). I definitely need practice, but I think I fall around 11-12, which puts me in the 23.2-25.3 BF%. I will try to get my husband to use the calipers on me, and see what the reading is. I just measured myself, and went to the Body Tracker Pro site you linked above, and it says 23.3%.

So pfffft to Withings!

Mike, I weigh every morning when I wake up, and my feet are pretty dry then. I jumped on the scale yesterday after boot camp, and my feet were definitely sweaty (omg that guy killed us yesterday), and I was 28% (as opposed to typical 30-31%). So your info about foot dampness was on the money for me!

Although I am definitely not an expert on this subject I disagree with the caliper method being the favoured choice. I am an athletic 26 year-old woman, and I recently had my body fat % estimated by one of the trainers with a caliper. She had estimated my BF at 13.6%. I have a scale at home (bio-scale) that had been estimating my BF between 20 – 23% during that same period. I recently had my metabolism tested at a facility that does nutrition programs for weight loss and for performance enhancement, and they use a machine that runs a current through the body, while you are laying down. They measured me at 20.1%.
I’m sure the caliper method is accurate for those who are skilled at using it, but I don’t think it would be a good idea for someone to use it if they aren’t practiced. If they underestimated my BF by almost 10%, that could be a real hindrance for somebody hovering in the obese range who thinks everything is fine. That would be enough for someone to lose the motivation to lose weight if a woman thinks she is in the healthy range at 24%, when she could really be at 34%!

@Leigh – I appreciate your opinion, but I would have to say that trainer sounds like she had no idea what she was doing! Unless you look extremely lean, a 13.6% BF is just way off and she should have known that. My guess is 9 out of 10 trainers would do a decent job. Before making a final conclusion, I would try out the single site Accumeasure body fat caliper to see what the reading is. For now, I still prefer the caliper, but thanks for sharing your opinion.

THX Marc
I just volunteered for a long term cancer study that includes among several others metrics measuring % body fat using a BIA. I was 22% just 3% off clinically obese. I don’t have six pack but I’m not far off! and I’m well proportioned otherwise. Calipers in the past measured 12% or less. I’m far less active the last 10 years but luckily look similar so I was a little concerned that I might have somehow snuck in a lot of hidden fat. The long term study is going to have some corrupted data IMO.

Hello Marc, I’ve recently been reading your blogs and articles very keenly. When it comes to Fat %, I am extremely confused. While my personal trainer measures it by using a caliper and tells me that my Fat % is now 17.5 %, the InBody machine tells my that I have a 26.2% of body fat.

In this case, having a variance of almost 9%, whom should I trust ? Can you please advise?

@Manoj – If I were you, I would get one more personal trainer to measure my body fat and see what happens. My guess is the caliper is likely more accurate. Also, check out this link for what approximate body fat percentages look like – http://bit.ly/MuqZMF.

@hien – skinfold calipers is what I use, I typically use the Jackson Pollock method, although I’ve found the single site Accumeasure to be pretty good as well. But hands down, skin fold calipers is the way to go if you have under 30% body fat.

ABOUT MARC PERRY

BuiltLean Creator

Marc Perry, CSCS, CPT is the creator of BuiltLean based in NYC. He is the go-to fitness expert for helping busy professionals get lean with strength circuits™. He's been featured on NBC, CBS, FOX, Men's Health ...